Albert-Baskar Arul, Na-Young Han, Y. Jang, Hyo-Jin Kim, Hwan‐Mook Kim, Hookeun Lee
Abstract : Various efforts have been developed to improve sample preparation steps, which strongly depend on hands-on processesfor accurate and sensitive quantitative proteome analysis. In this study, we carried out heating the sample prior to trypsin di gestion usingan instrument to improve the tryptic digestion process. The heat shock generated by the system efficiently denatured proteins in thesample and increased the reproducibility in quantitative proteomics based on peptide abundance measurements. To demonstrate theeffectiveness of the protocol, three cell lines (A human lung cancer cell line (A549), a human embryonic kidney cell line (HEK293T),and a human colorectal cancer cell line (HCT-116)) were selected and the effect of heat shock was compared to that of normal trypticdigestion processes. The tryptic digests were desalted and analysed by LC-MS/MS, the results showed 57 and 36% increase in thenumber of identified unique peptides and proteins, respectively, than conventional digestion. Heat shock treated samples showed highernumbers of shorter peptides and peptides with low inter-sample variation among triplicate runs. Quantitative LC-MS/MS analysis ofheat shock treated sample yielded peptides with smaller relative error percentage for the triplicate run when the peak areas were com-pared. Exposure of heat-shock to proteomic samples prior to proteolysis in conventional digestion process can increase the digestionefficiency of trypsin resulting in production of increased number of peptides eventually leading to higher proteome coverage.Keywords : Denaturation, mass spectrometry, proteolysis, Heat shock
{"title":"Effects of Heat Shock Treatment on Enzymatic Proteolysis for LC-MS/MS Quantitative Proteome Analysis","authors":"Albert-Baskar Arul, Na-Young Han, Y. Jang, Hyo-Jin Kim, Hwan‐Mook Kim, Hookeun Lee","doi":"10.5478/MSL.2016.7.1.1","DOIUrl":"https://doi.org/10.5478/MSL.2016.7.1.1","url":null,"abstract":"Abstract : Various efforts have been developed to improve sample preparation steps, which strongly depend on hands-on processesfor accurate and sensitive quantitative proteome analysis. In this study, we carried out heating the sample prior to trypsin di gestion usingan instrument to improve the tryptic digestion process. The heat shock generated by the system efficiently denatured proteins in thesample and increased the reproducibility in quantitative proteomics based on peptide abundance measurements. To demonstrate theeffectiveness of the protocol, three cell lines (A human lung cancer cell line (A549), a human embryonic kidney cell line (HEK293T),and a human colorectal cancer cell line (HCT-116)) were selected and the effect of heat shock was compared to that of normal trypticdigestion processes. The tryptic digests were desalted and analysed by LC-MS/MS, the results showed 57 and 36% increase in thenumber of identified unique peptides and proteins, respectively, than conventional digestion. Heat shock treated samples showed highernumbers of shorter peptides and peptides with low inter-sample variation among triplicate runs. Quantitative LC-MS/MS analysis ofheat shock treated sample yielded peptides with smaller relative error percentage for the triplicate run when the peak areas were com-pared. Exposure of heat-shock to proteomic samples prior to proteolysis in conventional digestion process can increase the digestionefficiency of trypsin resulting in production of increased number of peptides eventually leading to higher proteome coverage.Keywords : Denaturation, mass spectrometry, proteolysis, Heat shock","PeriodicalId":18238,"journal":{"name":"Mass Spectrometry Letters","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2016-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80384417","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Patel, M. Ditiatkovski, L. Kennedy, A. Oglobline, N. Choi, G. Richardson
Abstract : Results of free and bound myo-inositol in infant formula (IF) are presented. Inositol was analyzed by HILIC ultra-performance liquid chromatography coupled with mass spectrometer. The levels of free myo-inositol in 27 Australian and 4 EUoriginated IF samples were 300-600 mg/kg of powder or 1.6-3.1 mg/100 kJ. The amount of bound inositol in lipid fraction of IFwas, on average, 10% of free myo-inositol.Keywords : infant formula, myo-inositol, survey, UPLC-MS/MS. Introduction Inositol is an important nutrient present naturally inhuman milk and cow’s milk but in a lesser quantity. It existspredominantly in the free myo-inositol form. myo-Inositol isfound in large amounts in plant materials such as soy beansbut is in the bound form, predominantly as polyphosphate andin a lesser extent as phosphatidylinositol.The levels of inositol in infant formula are regulated.CODEX 1 defines lower and upper levels of inositol at 1 and9.5 mg/100 kJ. In the USA there is no prescribed limits 2 forinositol in dairy-based IF. The minimum amount of inositolin non-dairy based IF according to the Code of FederalRegulations (CFR) is 4 mg/100 kcal (~1 mg/100 kJ) and theupper limit is not regulated. The levels of inositol in IF inAustralia and New Zealand are regulated by the FSANZ2.9.1 and in China by the GB 10765-2010 Food Standards,Table 1.There are nine isomers of inositol C
{"title":"Survey of Inositol in Infant Formula","authors":"A. Patel, M. Ditiatkovski, L. Kennedy, A. Oglobline, N. Choi, G. Richardson","doi":"10.5478/MSL.2016.7.1.12","DOIUrl":"https://doi.org/10.5478/MSL.2016.7.1.12","url":null,"abstract":"Abstract : Results of free and bound myo-inositol in infant formula (IF) are presented. Inositol was analyzed by HILIC ultra-performance liquid chromatography coupled with mass spectrometer. The levels of free myo-inositol in 27 Australian and 4 EUoriginated IF samples were 300-600 mg/kg of powder or 1.6-3.1 mg/100 kJ. The amount of bound inositol in lipid fraction of IFwas, on average, 10% of free myo-inositol.Keywords : infant formula, myo-inositol, survey, UPLC-MS/MS. Introduction Inositol is an important nutrient present naturally inhuman milk and cow’s milk but in a lesser quantity. It existspredominantly in the free myo-inositol form. myo-Inositol isfound in large amounts in plant materials such as soy beansbut is in the bound form, predominantly as polyphosphate andin a lesser extent as phosphatidylinositol.The levels of inositol in infant formula are regulated.CODEX 1 defines lower and upper levels of inositol at 1 and9.5 mg/100 kJ. In the USA there is no prescribed limits 2 forinositol in dairy-based IF. The minimum amount of inositolin non-dairy based IF according to the Code of FederalRegulations (CFR) is 4 mg/100 kcal (~1 mg/100 kJ) and theupper limit is not regulated. The levels of inositol in IF inAustralia and New Zealand are regulated by the FSANZ2.9.1 and in China by the GB 10765-2010 Food Standards,Table 1.There are nine isomers of inositol C","PeriodicalId":18238,"journal":{"name":"Mass Spectrometry Letters","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2016-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88213670","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sumin Park, G. Choi, S. Lee, Hyun Jeong Kim, H. Yum, K. Paeng
Simultaneous determination of three corticosteroids (clobetasol propionate, betamethasone dipropionate, fluticasone propionate) in moisturizers was performed by using liquid chromatography (LC) coupled with tandem mass spectrometry (MS/ MS). Sample preparation was conducted by the liquid-liquid extraction (LLE). Moisturizers include emulsifying agent and it forms micelles. In order to improve the extraction efficiency of corticosteroids trapped in micelle, newly developed-optimized extraction conditions which can remove the matrix effect from moisturizers was applied with various pH conditions in LLE extraction stage of sample preparation. Thus, the addition of 10 µL of 1 M HCl into moisturizers sample before extraction could improve the extraction efficiency. For the quantitative analysis, SRM table that contained specific transition of all of target corti- costeroids was created. The developed method was validated for linearity, accuracy, precision, limit of detection (LOD), limit of quantization (LOQ) and recovery. Over the 0.99 r 2 value was obtained in calibration standard range. Effective accuracy and pre- cision were also obtained. LODs were below 31 ng/mL and LOQs were estimated below 94 ng/mL for all corticosteroids tested.
{"title":"Determination of Corticosteroids in Moisturizers by LC-MS/MS","authors":"Sumin Park, G. Choi, S. Lee, Hyun Jeong Kim, H. Yum, K. Paeng","doi":"10.5478/MSL.2016.7.1.26","DOIUrl":"https://doi.org/10.5478/MSL.2016.7.1.26","url":null,"abstract":"Simultaneous determination of three corticosteroids (clobetasol propionate, betamethasone dipropionate, fluticasone propionate) in moisturizers was performed by using liquid chromatography (LC) coupled with tandem mass spectrometry (MS/ MS). Sample preparation was conducted by the liquid-liquid extraction (LLE). Moisturizers include emulsifying agent and it forms micelles. In order to improve the extraction efficiency of corticosteroids trapped in micelle, newly developed-optimized extraction conditions which can remove the matrix effect from moisturizers was applied with various pH conditions in LLE extraction stage of sample preparation. Thus, the addition of 10 µL of 1 M HCl into moisturizers sample before extraction could improve the extraction efficiency. For the quantitative analysis, SRM table that contained specific transition of all of target corti- costeroids was created. The developed method was validated for linearity, accuracy, precision, limit of detection (LOD), limit of quantization (LOQ) and recovery. Over the 0.99 r 2 value was obtained in calibration standard range. Effective accuracy and pre- cision were also obtained. LODs were below 31 ng/mL and LOQs were estimated below 94 ng/mL for all corticosteroids tested.","PeriodicalId":18238,"journal":{"name":"Mass Spectrometry Letters","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2016-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74406882","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jongwha Lee, M. Park, Jeongmin Ju, Yun-Sang Choi, Soo Min Hwang, D. Jung, Hugh Inkon Kim
: Characterization of intact protein structures in the gas phase using electrospray ionization combined with ion mobility mass spectrometry has become an important tool of research. However, the biophysical properties that govern the structures of protein ions in the gas phase remain to be understood. Here, we investigated the impact of host-guest complexation of ubiquitin (Ubq) with macrocyclic host molecules, cucurbit[ n ]urils (CB[ n ]s, n = 6, 7), on its structure in the gas phase. We found that CB[ n ] complexation induces the formation of compact Ubq ions. Both CB[6] and CB[7] exhibited similar effects despite differences in their binding properties in solution. In addition, CB[ n ] attachment prevented Ubq from unfolding by collisional activation. Based on the experimental results, we suggest that CB[ n ]s prevent unfolding of Ubq during transfer to the gas phase to promote the formation of compact protein ions. Furthermore, interaction with positively charged residues per se is suggested to be the most important factor for the host-guest complexation effect.
电喷雾电离结合离子迁移率质谱法表征气相中完整蛋白质结构已成为重要的研究工具。然而，控制蛋白质离子在气相中的结构的生物物理性质仍有待了解。在这里，我们研究了泛素(Ubq)与大环宿主分子葫芦[n]urils (CB[n]s, n = 6,7)的主客体络合作用对其气相结构的影响。我们发现，CB[n]络合可诱导致密Ubq离子的形成。尽管CB[6]和CB[7]在溶液中的结合特性不同，但其效果相似。此外，CB[n]的粘附阻止Ubq通过碰撞激活展开。基于实验结果，我们认为CB[n]s在Ubq向气相转移过程中阻止了Ubq的展开，从而促进了致密蛋白离子的形成。此外，与带正电残基本身的相互作用被认为是主客体络合效应的最重要因素。
{"title":"Stabilization of Compact Protein Structures by Macrocyclic Hosts Cucurbit[n]urils in the Gas Phase","authors":"Jongwha Lee, M. Park, Jeongmin Ju, Yun-Sang Choi, Soo Min Hwang, D. Jung, Hugh Inkon Kim","doi":"10.5478/MSL.2016.7.1.16","DOIUrl":"https://doi.org/10.5478/MSL.2016.7.1.16","url":null,"abstract":": Characterization of intact protein structures in the gas phase using electrospray ionization combined with ion mobility mass spectrometry has become an important tool of research. However, the biophysical properties that govern the structures of protein ions in the gas phase remain to be understood. Here, we investigated the impact of host-guest complexation of ubiquitin (Ubq) with macrocyclic host molecules, cucurbit[ n ]urils (CB[ n ]s, n = 6, 7), on its structure in the gas phase. We found that CB[ n ] complexation induces the formation of compact Ubq ions. Both CB[6] and CB[7] exhibited similar effects despite differences in their binding properties in solution. In addition, CB[ n ] attachment prevented Ubq from unfolding by collisional activation. Based on the experimental results, we suggest that CB[ n ]s prevent unfolding of Ubq during transfer to the gas phase to promote the formation of compact protein ions. Furthermore, interaction with positively charged residues per se is suggested to be the most important factor for the host-guest complexation effect.","PeriodicalId":18238,"journal":{"name":"Mass Spectrometry Letters","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2016-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84126404","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-12-31DOI: 10.5478/MSL.2015.6.4.116
H. Yoon
Globotriaosylsphingosine (lyso-Gb3) is considered as one of the biological marker for Fabry disease. To date, a reli- able biomarker that reflects disease severity and progression has not been discovered to guide the management of Fabry disease. A new method included a simple protein precipitation with acetonitrile in 100 µL of plasma following analyte separation on an Phenomenex Kintex- C18 column using a gradient elution (0.1% formic acid in 5-90% acetonitrile). Total run time was within 12 min including sample preparation and MS/MS analysis. The limit of detection and limit of quantitation were 1 ng/mL and 2 ng/mL, respectively. The calibration curve was linear over the concentration range of 2.0-200.0 ng/mL (r 2 = 0.9999). Inter-day accuracy and precision at 7 level were 93.4-100.7% with RSD of 0.55-5.97%. Absolute recovery was 97.6-98.6%. The method was applied to human and mice plasma, proved the suitability for quantification of lyso-Gb3 for screening, diagnosis and thera- peutic monitoring of Fabry disease patients.
{"title":"A Fast Determination of Globotriaosylsphingosine in Plasma for Screening Fabry Disease Using UPLC-ESI-MS/MS","authors":"H. Yoon","doi":"10.5478/MSL.2015.6.4.116","DOIUrl":"https://doi.org/10.5478/MSL.2015.6.4.116","url":null,"abstract":"Globotriaosylsphingosine (lyso-Gb3) is considered as one of the biological marker for Fabry disease. To date, a reli- able biomarker that reflects disease severity and progression has not been discovered to guide the management of Fabry disease. A new method included a simple protein precipitation with acetonitrile in 100 µL of plasma following analyte separation on an Phenomenex Kintex- C18 column using a gradient elution (0.1% formic acid in 5-90% acetonitrile). Total run time was within 12 min including sample preparation and MS/MS analysis. The limit of detection and limit of quantitation were 1 ng/mL and 2 ng/mL, respectively. The calibration curve was linear over the concentration range of 2.0-200.0 ng/mL (r 2 = 0.9999). Inter-day accuracy and precision at 7 level were 93.4-100.7% with RSD of 0.55-5.97%. Absolute recovery was 97.6-98.6%. The method was applied to human and mice plasma, proved the suitability for quantification of lyso-Gb3 for screening, diagnosis and thera- peutic monitoring of Fabry disease patients.","PeriodicalId":18238,"journal":{"name":"Mass Spectrometry Letters","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2015-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78667417","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. S. Chaharborj, S. Kiai, Norihan Md Arifina, Y. Gheisari
The Brownian motion or Wiener process, as the physical model of the stochastic procedure, is observed as an indexed collection random variables. Stochastic procedure are quite influential on the confinement potential fluctuation in the quadrupole ion trap (QIT). Such effect is investigated for a high fractional mass resolution spectrometry. A stochastic procedure like the Wiener or Brownian processes are potentially used in quadrupole ion traps (QIT). Issue examined are the sta- bility diagrams for noise coefficient, as well as ion trajectories in real time for noise coefficient, . The simulated results have been obtained with a high precision for the resolution of trapped ions. Furthermore, in the lower mass range, the impulse voltage including the stochastic potential can be considered quite suitable for the quadrupole ion trap with a higher mass resolution.
{"title":"Applications of Stochastic Process in the Quadrupole Ion traps","authors":"S. S. Chaharborj, S. Kiai, Norihan Md Arifina, Y. Gheisari","doi":"10.5478/MSL.2015.6.4.91","DOIUrl":"https://doi.org/10.5478/MSL.2015.6.4.91","url":null,"abstract":"The Brownian motion or Wiener process, as the physical model of the stochastic procedure, is observed as an indexed collection random variables. Stochastic procedure are quite influential on the confinement potential fluctuation in the quadrupole ion trap (QIT). Such effect is investigated for a high fractional mass resolution spectrometry. A stochastic procedure like the Wiener or Brownian processes are potentially used in quadrupole ion traps (QIT). Issue examined are the sta- bility diagrams for noise coefficient, as well as ion trajectories in real time for noise coefficient, . The simulated results have been obtained with a high precision for the resolution of trapped ions. Furthermore, in the lower mass range, the impulse voltage including the stochastic potential can be considered quite suitable for the quadrupole ion trap with a higher mass resolution.","PeriodicalId":18238,"journal":{"name":"Mass Spectrometry Letters","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2015-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77604028","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract : This article reviews recent analytical techniques using inductively coupled plasma-mass spectrometry (ICP-MS)immunoassay for clinical and bio analysis. We classified the techniques into two categories, direct and indirect analysis, whichdepend upon a guideline of whether tagging materials are used or not. Direct analysis is well known, and generally used in con-junction with various other techniques, such as laser ablation, chromatographic separations, etc. Recently, indirect analysis u singtagging elements has intensively been discussed because of its importance in future applications to bio and clinical analysis,including environmental and food industries. The method has shown advantages of multiplex detection, excellent sensitivity, andshort analysis time owing to signal amplification and magnetic separation. Now, it expands the application field from small bio-molecules to large cells.Keywords : ICP-MS, Nanoparticle, Immunoassay, Particle tagging Introduction Inductively coupled plasma mass spectrometry (ICP-MS) is one of the most commonly used analyticalinstruments for metal detection in various fields owing toits noteworthy features, including high sensitivity to tracelevel elements, good linear dynamic range, multiplexdetection, and low detection limits.
{"title":"Analytical Techniques Using ICP-MS for Clinical and Biological Analysis","authors":"Jungaa Ko, H. B. Lim","doi":"10.5478/MSL.2015.6.4.85","DOIUrl":"https://doi.org/10.5478/MSL.2015.6.4.85","url":null,"abstract":"Abstract : This article reviews recent analytical techniques using inductively coupled plasma-mass spectrometry (ICP-MS)immunoassay for clinical and bio analysis. We classified the techniques into two categories, direct and indirect analysis, whichdepend upon a guideline of whether tagging materials are used or not. Direct analysis is well known, and generally used in con-junction with various other techniques, such as laser ablation, chromatographic separations, etc. Recently, indirect analysis u singtagging elements has intensively been discussed because of its importance in future applications to bio and clinical analysis,including environmental and food industries. The method has shown advantages of multiplex detection, excellent sensitivity, andshort analysis time owing to signal amplification and magnetic separation. Now, it expands the application field from small bio-molecules to large cells.Keywords : ICP-MS, Nanoparticle, Immunoassay, Particle tagging Introduction Inductively coupled plasma mass spectrometry (ICP-MS) is one of the most commonly used analyticalinstruments for metal detection in various fields owing toits noteworthy features, including high sensitivity to tracelevel elements, good linear dynamic range, multiplexdetection, and low detection limits.","PeriodicalId":18238,"journal":{"name":"Mass Spectrometry Letters","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2015-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75118190","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-12-31DOI: 10.5478/MSL.2015.6.4.112
S. S. Kiai, M. Elahi, S. Adlparvar, N. Nemati, S. Shafaei, L. Karimi
In this article, we examine the influences of Ne and He buffer gases under confined Ar + ion cloud in a homemade Paul ion trap in various pressures and confinement times. The trap is of small size (r0 = 1 cm) operating in a radio frequency (rf) voltage only mode, and has limited accuracy of 13 V. The electron impact and ionization process take place inside the trap and a Faraday cup has been used for the detection. Although the experimental results show that the Ar + ion FWHM with Ne buffer gas is wider than the He buffer gas at the same pressure (1×10 -1 mbar) and confinement time is about 1000 µs, nevertheless, a faster cooling was found with He buffer gas with 500 µs. ultimetly, the obtanied results performed an average cloud tempertures reduced from 1777 K to 448.3 K for Ne (1000 µs) and from 1787.9 K to 469.4 K for He (500 µs)
{"title":"Investigation of Ne and He Buffer Gases Cooled Ar + Ion Clouds in a Paul Ion Trap","authors":"S. S. Kiai, M. Elahi, S. Adlparvar, N. Nemati, S. Shafaei, L. Karimi","doi":"10.5478/MSL.2015.6.4.112","DOIUrl":"https://doi.org/10.5478/MSL.2015.6.4.112","url":null,"abstract":"In this article, we examine the influences of Ne and He buffer gases under confined Ar + ion cloud in a homemade Paul ion trap in various pressures and confinement times. The trap is of small size (r0 = 1 cm) operating in a radio frequency (rf) voltage only mode, and has limited accuracy of 13 V. The electron impact and ionization process take place inside the trap and a Faraday cup has been used for the detection. Although the experimental results show that the Ar + ion FWHM with Ne buffer gas is wider than the He buffer gas at the same pressure (1×10 -1 mbar) and confinement time is about 1000 µs, nevertheless, a faster cooling was found with He buffer gas with 500 µs. ultimetly, the obtanied results performed an average cloud tempertures reduced from 1777 K to 448.3 K for Ne (1000 µs) and from 1787.9 K to 469.4 K for He (500 µs)","PeriodicalId":18238,"journal":{"name":"Mass Spectrometry Letters","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2015-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79510761","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Mass Spectrometric Analysis for Discrimination of Diastereoisomers","authors":"N. Manshoor, J. Weber","doi":"10.5478/MSL.2015.6.4.99","DOIUrl":"https://doi.org/10.5478/MSL.2015.6.4.99","url":null,"abstract":"","PeriodicalId":18238,"journal":{"name":"Mass Spectrometry Letters","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2015-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77686183","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-12-01DOI: 10.5478/MSL.2015.6.4.105
N. Manshoor, J. Weber
: Sixteen compounds of Neobalanocarpus heimii were successfully identified directly from their plant extract using a triple quadrupole LC-MS/MS system. In order to fulfil the objectives of this work, a series of stilbene oligomers of various degrees of condensation were isolated and their structure are characterized. Out of these, four are resveratrol dimers, three trim-ers, and nine tetramers. The isolation process was done on a fully automated semi-preparative HPLC system. Their structures were elucidated on the basis of 1D- and 2D-NMR as well as MS data. The mass fragmentation patterns of the compounds were recorded and a retrievable in-house library was built to keep the data. In order to demonstrate the potential of this approach, the polyphenolic crude extract was analysed with the LC-MS/MS system and the MS/MS spectra extracted for each chromatographic peak of interest. The fragmentation patterns were compared with those of anticipated pure compounds that were previously recorded. All compounds were successfully identified. It is therefore believed that the LC-MS/MS potential for dereplication of structurally similar compounds in a crude mixture was thus firmly established.
{"title":"Mass Fragmentation Patterns as Fingerprints for Positive Identification of Polyphenolic Compounds in a Crude Extract","authors":"N. Manshoor, J. Weber","doi":"10.5478/MSL.2015.6.4.105","DOIUrl":"https://doi.org/10.5478/MSL.2015.6.4.105","url":null,"abstract":": Sixteen compounds of Neobalanocarpus heimii were successfully identified directly from their plant extract using a triple quadrupole LC-MS/MS system. In order to fulfil the objectives of this work, a series of stilbene oligomers of various degrees of condensation were isolated and their structure are characterized. Out of these, four are resveratrol dimers, three trim-ers, and nine tetramers. The isolation process was done on a fully automated semi-preparative HPLC system. Their structures were elucidated on the basis of 1D- and 2D-NMR as well as MS data. The mass fragmentation patterns of the compounds were recorded and a retrievable in-house library was built to keep the data. In order to demonstrate the potential of this approach, the polyphenolic crude extract was analysed with the LC-MS/MS system and the MS/MS spectra extracted for each chromatographic peak of interest. The fragmentation patterns were compared with those of anticipated pure compounds that were previously recorded. All compounds were successfully identified. It is therefore believed that the LC-MS/MS potential for dereplication of structurally similar compounds in a crude mixture was thus firmly established.","PeriodicalId":18238,"journal":{"name":"Mass Spectrometry Letters","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2015-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80858702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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